- What are the possible ways for communication between microservices?
- What is exchange in message queue?
- What are the benefits of microservices?
- What are the disadvantages of microservices?
- What are the possible issues in microservices
- What are the possible solutions for the case when one service is not available?
- What is the difference between synchronous and asynchronous communication?
- What are possible ways for implementing authentication in microservices?
- What is Eventual consistency?
- Synchronous protocol. HTTP is a synchronous protocol. The client sends a request and waits for a response from the service. That's independent of the client code execution that could be synchronous (thread is blocked) or asynchronous (thread isn't blocked, and the response will reach a callback eventually). The important point here is that the protocol (HTTP/HTTPS) is synchronous and the client code can only continue its task when it receives the HTTP server response.
- Asynchronous protocol. Other protocols like AMQP (a protocol supported by many operating systems and cloud environments) use asynchronous messages. The client code or message sender usually doesn't wait for a response. It just sends the message as when sending a message to a RabbitMQ queue or any other message broker.
- https://docs.microsoft.com/en-us/dotnet/architecture/microservices/architect-microservice-container-applications/communication-in-microservice-architecture
- https://dzone.com/articles/communication-between-microservices
Exchange: a queue aggregator that abstract away message queues and routes messages to the appropriate queue based on some predefined logic.
- Technology Heterogeneity
- Resilience
- Scaling
- Ease of Deployment
- Organizational Alignment
- Composability
- Optimizing for Replaceability
- https://stackoverflow.com/questions/34903605/microservices-what-are-pros-and-cons
- https://www.tiempodev.com/blog/disadvantages-of-a-microservices-architecture/
- Microservices Are More Complex
- Microservices Require Cultural Changes
- Microservices Are More Expensive
- Microservices Pose Security Challenges
https://www.tiempodev.com/blog/disadvantages-of-a-microservices-architecture/
- As if monitoring a monolith wasn’t hard enough
- Logging is distributed between services
- An issue that’s caused by one service, can cause trouble elsewhere
- Finding the root cause of problems
- Version management and cyclic dependencies between services
- The circuit breaker pattern is the solution to this problem. The basic idea behind the circuit breaker is very simple. You wrap a protected function call in a circuit breaker object, which monitors for failures. Once the failures reach a certain threshold, the circuit breaker trips, and all further calls to the circuit breaker return with an error or with some alternative service or default message, without the protected call being made at all. This will make sure system is responsive and threads are not waiting for an unresponsive call.
- Retry Logic
- https://blog.risingstack.com/designing-microservices-architecture-for-failure/
- https://dzone.com/articles/circuit-breaker-pattern
- Synchronous protocol. HTTP is a synchronous protocol. The client sends a request and waits for a response from the service. That's independent of the client code execution that could be synchronous (thread is blocked) or asynchronous (thread isn't blocked, and the response will reach a callback eventually). The important point here is that the protocol (HTTP/HTTPS) is synchronous and the client code can only continue its task when it receives the HTTP server response.
- Asynchronous protocol. Other protocols like AMQP (a protocol supported by many operating systems and cloud environments) use asynchronous messages. The client code or message sender usually doesn't wait for a response. It just sends the message as when sending a message to a RabbitMQ queue or any other message broker.
- Distributed Session Management
- Client Token
- Single sign-on
- Client Token with API Gateway
- Third-party application access
- Mutual Authentication
- https://medium.com/tech-tajawal/microservice-authentication-and-authorization-solutions-e0e5e74b248a
- https://medium.com/@marcus.cavalcanti/stateless-authentication-for-microservices-9914c3529663
Rather than ensuring that the system is in a consistent state all the time, instead we can accept that the system will get it at some point in the future. This approach is especially useful for long-living business operations.